Yarn tensioning means for knitting machines



July 29, 1958 F. P. TRUMPIO 2,844,950

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed March 15, 1956 2 Sheets-Sheet l *FILE J n /7 A 2/ {%/j 55 26 27 I v IN VEN TOR.

-Fran P 17am i0 ATTORNEY July 29; 1958 F. P. TRUMPIO 2,844,950

YARN TENSIONING MEANS FOR KNITTING MACHINES FiledMarqh 13, 1956 2 Sheets-Sheet 2 F1. E LE Flr3 7 IN V EN TOR.

Fan]; 1. Fum io BY M04 A TTORNE Y.

United States Patent 9 YARN TENSIONING MEANS FOR KNITTING MACHINES Frank P. Trumpio, Temple, Pa., assignor to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Application March 13, 1956, Serial No. 571,316

8 Claims. (CI. 66-86) This invention relates to warp knitting machines such as high speed tricot machines, and more particularly to means in such machines to take up the yarns and maintain a constant and uniform tension in the yarns during the knitting of the same into fabric.

In textile fabricating machines such as tricot knitting machines and the like, a plurality or sheet of yarns are withdrawn from supply beams and are fed or directed along a predetermined path to the needles or fabricating means where they are formed into fabric. Between the supply beams and the needles the yarns pass over guiding and tensioning means which continuously acts to take up and maintain the yarns under predetermined tension as the needles are operated to knit the yarns into loops. In one common form, the tensioning means includes a rod extending the full length of the working portion of the machine, the rod being supported on the ends of levers which are spaced along and supported for oscillating movement on a shaft fixed in the framework of the machine. The movements of the levers are controlled by springs or the like which act on portions of the levers at the opposite side of the supporting shaft from the tension rod to resiliently maintain the rod in engagement with the yarns and permit the levers and rod to oscillate to follow the fluctuatingdemands for the yarns. With this construction the pressure exerted by the yarns and the springs on the levers at opposite sides of the supporting shaft creates substantial friction in the lever bearings which together with the weight mass of the levers and of the guide rod prevents the sensitive oscillating movements of the parts necessary to maintain the yarns under a uniform tension. This is particularly so in machines operating at high speeds, and results in the uneven feeding of the yarns and the formation of fabric of inferior quality.

In the other known forms of tensioning means, the rods are mounted on thin flexible sheet metal arms or other resiliently controlled means fixed on a supporting shaft which is adjustably carried in the machine frame. In these devices the shaft is adjusted to simultaneously fix the position of the arms in an attempt to regulate the initial tension applied to the yarns but as there is no way to adjust the positions of individual arms along the rod to correct variations of tension it is often found that an uneven tension is applied to the yarns by different parts of the guide rods.

It is accordingly an object of the invention to provide means in a warp knitting machine for uniformly applying tension on the yarns which means overcomes the above mentioned and other ditficulties encountered with the use of known devices.

Another object of the invention is to provide means for tensioning a plurality or sheet of yarns, particularly for use in tricot knitting machines, which means is carried on spaced members which are controlled by resilient means having individual adjustment to permit a uniform tension to be exerted on all of the yarns.

A further object of the invention is to provide a rod for guiding and tensioning a plurality of yarns which rod is ice carried on spaced members which are resiliently hinged in a manner to eliminate frictional engagement between the parts.

With these and other objects in view which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the novel elements, features of construction and cooperation of parts, as hereinafter more particularly pointed out in the claims.

In the drawings:

Figure l is a cross-sectional view taken transversely through a portion of a tricot knitting machine showing the knitting mechanism and yarn tensioning mechanism according to the invention, dot-and-dash distance breaks being shown to indicate the omission of intervening mechanism;

Fig. 2 is a plan view of the yarn tensioning mechanism as seen from the left of Fig. 1 and in the direction of the arrow A;

Fig. 3 is an elevational view of the tensioning mechanism on an enlarged scale taken in the direction of the arrows 33 on Fig. 2, parts of Fig. 2 being omitted;

Fig. 4 is a side elevational view of the mechanism as seen from the right of Fig. 3;

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a cross-sectionalvview taken along the line 6-6 of Fig. 4; and

Fig. 7 is a cross-sectional view taken substantially along the line 77 of Fig. 4.

Referring to the drawings, and particularly to Fig. 1, there is shown a portion of a tricot knitting machine including spring bearded needles 10, sinkers 11, a presser member 12 for closing the beards of the needles and front and rear groups of yarn guides 15 for yarns 16. The needles 10, sinkers 11 and presser member 12 are operated at high speeds in the usual manner to form the yarns 16, lapped around the needles by the yarn guides 15, into loops of the fabric. The yarns 16, for the front and rear groups of yarn guides follow separate upper and lower paths respectively, and are withdrawn from supply beams, portions of which are shown at 17 and 20, respectively. The yarns 16 in the upper path pass beneath a rod or shaft 21 which is supported in spaced bearing brackets 22, partially shown in Figs. 1 and 2, carried on a portion 25 of the framework of the machine. From the rod 21 the yarns 16 are directed through a comb device 26, carried on members 27 secured on a shaft 30 which in turn is mounted in bearing members 31 secured to the brackets 22. From the comb device, which acts to separate the individual yarns, the yarns pass over a guide rod 32 preferably of hollow light weight construction, to the frontgroup of yarn guides 15. The yarns 16 in the lower p'ath are directed beneath a shaft 35, also supported in the brackets 22 and through a comb device 36. The latter is carried on members 37, similar to the members 27, secured on a shaft 40 which in turn is mounted in bearing members 41 secured to the brackets 22. From the comb device 36 the yarns are directed over a guide rod 42 to the rear group of guides 15.

During the knitting operation of the machine the yarn guides 15 are moved through the needles 10 from their position of Fig. 1, then shifted transversely of the needle row and then back to the position of Fig. l to lap or loop the yarns around the needles and the needles are simultaneously operated to catch the yarns beneath the beards and to form and knit the yarns into loops of the fabric. This movement of the yarn guides 15 results in a variation in the demand for the yarns thereby tending to cause a periodic increase and decrease in the tension in the yarns between the yarn guides and guide rods 32 and 42. In order to maintain a constant tension in the yarns at this time, the guide rods 32 and 42 must be mounted to follow the rapidly varying demands for the yarns. For this purpose, the guide rod 32 for the yarns 16 in the upper path is carried at the free ends of a series of spaced rigid channel-shaped members or arms 45 by means of straps 46 which are secured to the members by screw and nut devices 47 (Figs. 3, 4 and Each channel-shaped member 45 is secured by screws 50 to the free end of a resilient member or plate 51 of spring steel or the like which is secured between a rigid plate 55 and an upper surface of a portion 56 of a bracket or support member 57 by means of screws 60. The plate 55 overhangs the right end of the channel-shaped member 45 to limit the upward movement of the channel-shaped member and is slotted at 58 (Fig. 2) to clear the heads of the screws 50. The bracket 57 is provided with a split bearing portion 61 and a screw 63 by means of which the bracket is secured in adjusted position on the shaft 30. Also secured by the screws 50 to the underside of the channel-shaped member 45 is bracket member 62 which carries a shouldered bushing 65 having a portion interfitting the inside diameter of the coils of a compression spring 66 to anchor one end of the spring. The spring 66 extends between walls 67 (Figs. 6 and7) joining the portion 56 to the bracket 57, to engage a shouldered portion .70 of a stud 71 threadably carried in a portion of the bracket (Fig. 5). A reduced head portion 72 of the stud 71 interfits within the inner diameter of the coils of the spring 66 and serves to anchor the right end of the spring. The head portion 72 of the stud 71 is provided with a screwdriver slot 73 whereby the stud may be adjusted in the bracket 57 by inserting a screwdriver through the bushing 65 and the interior of the coil spring, to increase or decrease the pressure of the spring 66 on the bracket member 62 and thereby control the tension exerted by the guide rod 32 on the yarns 16. The stud 71 is maintained in adjusted position in the bracket 57 by a set screw 75 (Fig. 4).

The guide rod 42 for the yarns 16 in the lower path is mounted and tensioned in the same manner as the guide rod 32, the paths being identical in structure and having like reference characters applied thereto.

From the foregoing it will be apparent that an eflicient tensioning means is provided by the instant invention that overcomes the objections of prior devices and attains the aforesaid objects. The plates 51 provide both support and friction free hinges for the guide rods 32 and 42 to facilitate the rapid movements of the guide rods under the influence of the springs 66 to constantly maintain the desired tension in the yarns 16.

Of course, the improvements specifically shown and described by which the above results are obtained, can be changed and modified in various ways without departing from the invention herein disclosed and hereinafter claimed.

I claim:

1. A yarn guiding and tensioning means for warp knitting machines or the like, comprising a support member, an arm, a yarn guide rod carried by said arm, a resilient spring member connecting said arm to said support member and permitting relative movement between said arm and said support member, and resilient means between said arm and support member acting to resist said relative movement in one direction.

2. In a warp knitting machine having means for supplying a sheet of yarns, means for forming said yarns into fabric, and means for applying tension to said yarns, said last named means comprising a guide rod, an arm on which said guide rod is carried, a support member, a resilient plate connecting said arm to said support member and permitting relative movement of said arm and said support member, and resilient means acting on said arm to resist said relative movement in one direction.

3. A yarn guiding and tensioning means for warp knitting machines, comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, a resilient spring member connecting said arm and said support member and permitting movement of said arm relative to said support member, resilient means between said arm and support member to resist said relative movement in one direction, and means for adjusting the resistance of said resilient means.

4. A yarn guiding and tensioning means for warp knitting machines, comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, a resilient spring member pivotally connecting said arm and said support member for relative movement, and spring means between said arm and said support member for resisting said relative movement in one direction.

5. In a warp knitting machine having means for supplying a sheet of yarns, means for forming said yarns into fabric, and means for applying tension to said yarns, said last named means comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, a resilient plate connecting said arm to said support member and permitting relative movement therebetween, and adjustable spring means acting on said arm to resist said relative movement in one direction.

6. In a warp knitting machine having means for supplying a sheet of yarns, means for forming said yarns into fabric, and means for applying tension to and for taking up the slack in said yarns, said last named means comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, resilient plate connecting said arm to said support member and permitting relative movement therebetween, spring means acting on said arm to resist said relative movement in one direction, and stop means to limit the movement of said arm in the opposite direction.

7. In a warp knitting machine having means for supplying a sheet of yarns, means for forming said yarns into fabric, and means for applying tension to and for taking up slack in said yarns, said last named means comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, a resilient plate connecting said arm to said support member and permitting relative movement between said arm and support member, spring means, and means on said arm and support member for supporting said spring means in position to resist said relative movement in one direction.

8. In a warp knitting machine for supplying a sheet of yarns, means for forming said yarns into fabric, and means for applying tension to and for taking up slack in said yarns, said last named means comprising a guide rod over which said yarns are directed, an arm on which said guide rod is carried, a support member, a resilient plate connecting said arm to said support member to permit relative movement between said arm and support member, spring means between said arm and said support member to resist said relative movement, and means for supporting said spring means between said arm and said support member including a threaded member carried in said support member.

References Cited in the file of this patent UNITED STATES PATENTS 1,625,156 Rigby Apr. 19, 1927 2,308,430 Bolden et al Jan. 12, 1943 2,637,184 Schoenster May 5, 1953 2,667,773 Hepp Feb. 2, 1954 2,777,309 Newton Jan. 15, 1957 FOREIGN PATENTS 4,333 Great Britain of 1890 

